Weight Percentage Research Articles

Durability Investigation of Low Pt-Loaded PEM Fuel Cells with Different Catalyst Layer Morphologies

This study investigates the durability of proton exchange membrane fuel cells against the Pt-dissolution degradation mechanism using a triangular accelerated stress test (AST) within the voltage range of 0.6-1 V. The electrochemical active surface area and polarization curves are reported throughout the AST for three different catalyst layers (CL), all featuring 0.1 mg/cm2 Pt loading but with different morphologies, which include the Pt/C weight percentages, dilution ratio, and thickness. In addition, a numerical model is employed to simulate the electrochemical performance of these samples at the beginning and end of life, considering the variations in the oxygen transport resistances and catalyst structure.

Exploring the Structural, Morphological, and Multiferroic Properties of Al3+ Modified (1-x)BCZT-(x)CFO Ceramic Composites

Abstract Multiferroics with strong magnetoelectric coupling can be created by improving the magnetostriction of the ferrite phase and combining it with the best known piezoelectric. Herein, the ferromagnetic CoFe2O4 was modified with Al3+ ions (CAF) to further improve the resistivity, magnetic, and magnetostrictive properties and then combined with (0.5)Ba(Zr0.2Ti0.8)O3−(0.5)(Ba0.7Ca0.3)TiO3(BCZT) with different weight percentages. XRD results revealed the presence of a mixed spinel cubic phase for CAF (Fd-3m), whereas BCZT crystallized in a tetragonal structure (Amm2) in composite systems. Composites exhibited well-developed hysteresis loops with no feature of leakage current and dielectric response was consistent with ferroelectric properties. The magnetic response of CAF sample improved significantly which is attributed to preference of Al3+ ions on tetrahedral sites. The magnetization of composites increased as the nonmagnetic BCZT component increased and (0.75)CAF-(0.25)BCZT system had the highest saturation magnetization. We anticipate that these systems will have significantly improved magnetoelectric characteristics than unmodified CF-BCZT system.

Simulation model of carbon capture with MEA and the effect of temperature and duty on efficiency

Humans continue to rely on fossil fuels to generate electricity. In other words, fossil fuels are the world's largest energy producers. Fossil fuels produce significant carbon dioxide, mostly in areas where humans live. Although the share of carbon dioxide produced in big cities is minimal compared to the carbon dioxide production of volcanoes, the production of carbon dioxide in big cities has destructive effects. Process Simulator is utilized to evaluate the effectiveness of their simulation model by subjecting it to various experimental conditions, including liquid loading, temperature, and CO2 absorption (PPS). Comparing empirical and simulated mass transfer coefficients distinguishes this study from others. This procedure consists of two steps: Carbon dioxide (CO2) absorption in a solvent produces highly concentrated CO2 gas following solvent regeneration. A chemical adsorption process's scalability depends on accurate simulation models, typically validated using data from a pilot plant. With the aid of this study, a simulation model of a desorption column is constructed with ASPEN PLUS and 42% MEA validated. In addition, the effect of the weight percentage of 20-42 MEA in the inlet stream on the efficiency is investigated, and the influence of the MEA inlet temperature on system efficiency is examined. Then, the recommended temperature is confirmed based on the MEA's heat tolerance capacity of 303 Kelvin.

Impact of Zinc Oxide on Dielectric Properties of Forsterite Coated Titanium Based Medical Implants

Abstract Zinc oxide-doped forsterite solutions are synthesized through the sol-gel approach by varying the weight percentage of zinc oxide. These solutions are then applied to titanium (Ti) substrates to form zinc oxide-doped forsterite coated Ti substrate samples using the dip-coating method. The structural and surface morphology analyses of the samples are conducted using X-ray Diffraction (XRD) and Scanning Electron Microscope (SEM). Dielectric properties, encompassing dielectric constant, dielectric loss, alternating current conductivity, loss tangent, and relaxation time are explored at room temperature over a frequency range of 200 MHz to 20 GHz utilizing a Vector Network Analyzer (VNA) setup. The impact of zinc oxide on the structure, morphology, and dielectric properties of the samples, particularly in medical implant applications, is extensively discussed. The results indicate that samples with a higher weight percentage of zinc oxide demonstrate superior dielectric characteristics.

Effect of nano-particle weight percent on the flexural strength of Jute/kenaf/glass fiber composite using RSM

Effect of nano-particle weight percent on the flexural strength of Jute/kenaf/glass fiber composite using RSM

Text Messages With Financial Incentives for Men With Obesity: A Randomized Clinical Trial.

Effective weight loss interventions are needed for men with obesity. To determine whether an intervention that combined text messaging with financial incentives attained significant weight loss at the 12-month follow-up compared with the control group and whether an intervention of text messaging alone attained significant weight loss at the 12-month follow-up compared with the control group. An assessor-blinded randomized clinical trial conducted in Belfast, Bristol, and Glasgow areas in the UK. A total of 585 men with body mass index (BMI) of 30 or more were enrolled between July 2021 and May 2022. Final follow-up occurred June 2023. Participants were randomly assigned to 12 months of behavioral focused text messages combined with financial incentives (n = 196), 12 months of behavioral focused text messages alone (n= 194), or a waiting list (control group; n= 195). The financial incentive consisted of a monetary reward that was lost if weight loss targets were not met. All participants received weight management information and a pedometer at baseline. The 2 primary comparisons were the 12-month comparison of within-participant weight change between the text messaging with financial incentive group and the control group and the comparison between the text messaging alone group and the control group (minimum clinically important difference, 3%). The P value defined for statistical significance was P < .025 for each comparison. Of the 585 men (mean [SD] age, 50.7 [13.3] years; mean weight, 118.5 [19.9] kg; mean BMI, 37.7 [5.7]; 525 [90%] White), 227 (39%) lived in postal code areas with lower socioeconomic status, and 426 (73%) completed the 12-month follow-up. At the 12-month follow-up, compared with the control group, the mean percent weight change was significantly greater in the text messaging with financial incentive group (mean difference, -3.2%; 97.5% CI, -4.6% to -1.9%; P < .001) but was not significantly greater in the text messaging alone group (mean difference, -1.4%; 97.5% CI, -2.9% to 0.0, P = .05). The mean (SD) weight changes were -5.7 (7.4) kg for the text messaging with financial incentives group, -3.0 (7.5) kg for the text messaging alone group, and -1.5 (6.6) kg for the control group. The 12-month mean (SD) percentage weight changes from baseline were -4.8% (6.1%) for the text messaging with financial incentives group, -2.7% (6.3%) for text messaging alone group, and -1.3% (5.5%) for the control group. Of 366 adverse events reported, the most common were infections (83 [23%]). Of the 23 serious adverse events (6.3%), 12 (52%) occurred in the text messaging with financial incentives group, 5 (22%) in the texts messaging alone group, and 6 (26%) in the control group. None were considered related to participating in a trial group. Among men with obesity, an intervention with text messaging with financial incentive significantly improved weight loss compared with a control group, whereas text messaging alone was not significantly better than the control condition. These findings support text messaging combined with financial incentives to attain weight loss in men with obesity. isrctn.org Identifier: ISRCTN91974895.

Mechanical Characterization of Hybrid Bagasse/Eggshell/E-glass Fiber-based Polyester Composite

Currently, numerous researchers, scientists, and industrialists are drawn towards utilizing natural fillers rather than synthetic ones because of their environmentally-friendly characteristics, lower density per unit volume and favorable mechanical attributes. Several studies have demonstrated that using organic filler in polyester matrix composites, instead of disposing of them in landfills, has various advantages. The current study focuses on the investigation of the mechanical characteristics of composite material made from a combination of bagasse, eggshell, and e-glass fibers exhibit characteristics such as strength under tension, strength under bending, resistance to indentation, and mass per unit volume. Different weight percentages of eggshell/bagasse were used to make the material using the hand lay-up technique (3wt%, 6wt%, 9wt%, and 12wt%), with 19wt% of glass fiber mixed in the resin. The use of inorganic fillers like calcium carbonate, a non-renewable mineral that may be expensive and environmentally hazardous to extract and process, is being reduced in favor of organic fillers like eggshell and bagasse, which are inexpensive and readily available. Specimens were generated by interposing fiber waste amidst chopped strand glass fiber mats, with variations in the bagasse, eggshell and polyester content, while keeping the amount of E-glass fiber constant. Afterward, the specimens were trimmed to the appropriate dimensions and subjected to analysis with a universal apparatus. The research showed that enhancing the quantity of bagasse/eggshell fiber within the hybrid composite resulted in an enhancement of its mechanical characteristics. The best reinforcement effect was observed in a hybrid composite with 6% bagasse/eggshell fiber.

Comparison of perlite and pumice effects on the geotechnical properties of saline silty soil

ABSTRACT This research mainly sought to evaluate the sediments of the Urmia lake bed to prevent their erosion and the possibility of improving the problematic saline fine soils in the region by the geo-polymerisation process. For this purpose, perlite and pumice materials, with pozzolanic properties and weight percentages of 3, 5, and 7, were separately mixed with soil, along with the calcium hydroxide (Ca(OH)2) solution as a catalyst with 2%, 5%, and 7%. Then, the samples were cured for one day. Uniaxial compressive strength (UCS), direct shear, and consolidation tests were performed to assess the geotechnical properties of improved soil compaction. The results revealed that, compared to pumice, perlite could improve the behavioural properties of the studied soil. The inclusion of perlite and pumice, along with calcium hydroxide, increased the flexibility of the stabilised soil, as indicated by the brittleness index. Similarly, combining 3% perlite with 2% Ca(OH)2 could increase UCS at failure by 3.27 times. In addition, the mixture of 5% perlite with 7% Ca(OH)2 could enhance the shear strength by 3.3 times. Finally, combining 3% perlite with 5% calcium hydroxide reduced the swelling of the improved soil by 82%, and the consolidation settlement was decreased by 64% on average.

Differences in weight-loss outcomes among race-gender subgroups by behavioural intervention delivery mode: An analysis of the POWER trial.

Prior in-person behavioural intervention studies have documented differential weight loss between men and women and by race, with Black women receiving the least benefit. Remotely delivered interventions are now commonplace, but few studies have compared outcomes by race-gender groups and delivery modality. We conducted a secondary analysis of POWER, a randomized trial (NCT00783315) designed to determine the effectiveness of 2 active, lifestyle-based, weight loss interventions (remote vs. in-person) compared to a control group. Participants with obesity and at least one cardiovascular disease risk factor (N = 415) were recruited in the Baltimore, MD area. Data from 233 white and 170 Black individuals were used for this analysis. Following an intention-to-treat approach, we compared the mean percent weight loss at 24 months by race-gender subgroups using repeated-measures, mixed-effects models. Everyone lost weight in the active interventions however, weight loss differed by race and gender. white and Black men had similar results for both interventions (white: in-person (-7.6%) remote (-7.4%); Black: in-person (-4.7%) remote (-4.4%)). In contrast, white women lost more weight with the in-person intervention (in-person (-7.2%) compared to the remote (-4.4%)), whereas Black women lost less weight in the in-person group compared to the remote intervention at 24 months (-2.0% vs. -3.0%, respectively; p for interaction <.001). We found differences between the effectiveness of the 2 weight loss interventions-in-person or remote-in white and Black women at 24 months. Future studies should consider intervention modality when designing weight loss interventions for women.

Influence of MoS2 nano-filler additions on wear behavior of carbon fiber reinforced epoxy composites

In this research work, two body wear and three-body wear performance of carbon fabric reinforced HTR 212 epoxy resin(CF/Epoxy) composites are experimentally evaluated. Carbon fabric/epoxy resin composite panels with MoS2 nano-filler additions of 0.1, 0.2, 0.4 and 0.7 weight percentage are developed by Vacuum Assisted Resin Transfer Molding process. Two Body Wear test is conducted on the prepared specimen in accordance with ASTM G-99, whereas Three Body Abrasive wear test is conducted as per ASTM G-65. Experimental Tests are conducted for sliding and abrading distances in multiples of 250 m up to 1500 m. Results reveal that Carbon fabric/epoxy resin composites with 0.7 weight percent of MoS2 show 18% reduction in two body wear compared to a decrease of 35% in Three Body abrasive wear at 1500 m abrading distance. Scanning Electron Microscopy is used to study the surface morphology of the tested samples and to know the mode of damage at the surface.

Investigation on mechanical and thermal behaviour of graphene bonded carbon/Kevlar hybrid fabric polymer composites

The present research is aimed to understand the influence of graphene-reinforced carbon/Kevlar hybrid fabric epoxy composites. Samples HG0, HG2, HG4, and HG6 are fabricated using four layers of fabric mat and with varying graphene weight percentage as 0, 2, 4, and 6 wt.%, respectively. Mechanical characterizations such as hardness, tensile, and flexural strength were individually assessed. Thermal stability is evaluated through thermos-gravimetric analysis. Composite HG6 with high filler loading showed 71% and 114.4% greater tensile and flexural strength compared to unfilled HG0 specimen. Similarly, HG6 exhibited greater thermal stability. Inclusion of graphene particles in higher concentration improved the interfacial bonding between fibre/matrix/filler system. Fracture surfaces are analysed using scanning electron microscopy to understand the failure mechanisms.

The role of pantothenic acid in alleviating hypoxia-induced liver injury of sub-adult grass carp (Ctenopharyngodon idellus): Possible mechanisms and implication

In aquaculture, hypoxia poses a significant threat to fish growth and survival. Despite this, there is limited research on the impact of pantothenic acid (PA) in enhancing the anti-hypoxia stress capability of fish. The primary objective of this study was to explore the effects and potential mechanisms of PA in alleviating hypoxia-induced liver injury in sub-adult grass carp. To achieve this, six experimental diets containing varying levels of PA (0.08, 11.95, 24.95, 37.95, 50.95, and 63.95 mg/kg) were formulated and administered to grass carp (initial weight 696.22 ± 2.45 g) for 63 days. Following the dietary intervention, the fish were segregated into hypoxia and control groups and treated for 96 h. The findings revealed that optimal PA levels could enhance the growth performance of sub-adult grass carp and ameliorate the adverse impacts of hypoxia. First, optimal PA levels reduced serum levels of glutamate-oxaloacetate transaminase (GOT), glutamate-pyruvate transaminase (GPT), and lactate dehydrogenase (LDH), as well as mitigated hepatocyte vacuolization, improved liver and mitochondrial morphology, thereby alleviating hypoxia-induced liver injury. Furthermore, optimal PA levels were associated with increased contents of serum cortisol, glucose, liver glycogen, pyruvate, and the activities of Pantothenate kinase 2 (PanK2) and coenzyme A (CoA), while liver lactate content and LDH activity were reduced, indicating improvements in energy metabolism and PA utilization, potentially mediated by the down-regulation of hypoxia-inducible factor-1α (HIF-1α) mRNA level. Moreover, optimal PA levels decreased reactive oxygen species (ROS) and malondialdehyde (MDA) levels, enhanced liver antioxidant capacity, down-regulated autophagy-related gene mRNA levels, and up-regulated autophagy receptor protein 62 (p62) protein level, suggesting a reduction in oxidative damage and autophagy. Finally, a rise in levels of mitochondrial quality control-related mRNAs such as mitofusin 1/2 (MFN1/2), dynamin-related protein-1 (DRP-1), and nuclear respiratory factor 1/2 (Nrf-1/2) was observed, together with increment in the protein levels of PTEN induced putative kinase 1 (PINK1), BCL-2 interacting protein 3 (BNIP3) and FUN14 domain-containing protein 1 (FUNDC1). These alterations hinted at the role of PA in preserving mitochondrial homeostasis. In conclusion, PA exhibited a protective role against hypoxia-induced liver injury by enhancing liver energy metabolism, bolstering antioxidant defenses, suppressing autophagy, and maintaining mitochondrial homeostasis. Through an assessment of percentage weight gain (PWG) and liver ROS level, the requirements of PA for promoting growth and resilience to hypoxia-induced liver injury in sub-adult grass carp were determined to be 37.44 mg/kg and 42.57 mg/kg, respectively.

Optimization methods in powder metallurgy for enhancing the mechanical properties: A systematic literature review

Abstract Powder metallurgy offers several advantages over traditional manufacturing methods, such as improved material utilization and waste reduction. The powder metallurgy process involves four primary steps, metal powder preparation, mixing, compaction, and sintering, followed by secondary operations such as forging, rolling, and extrusion. However, existing studies have predominantly focused on refining the primary processes, neglecting secondary processes that could further enhance mechanical properties. A systematic literature review following the Preferred Reporting Items for Systematic Review and Meta-Analysis method identified twenty-three relevant articles over a ten-year period, highlighting three main optimization methods, that are, the Taguchi method, Taguchi-based Grey Relational Analysis, and Response Surface Methodology. These methods effectively reduce experimental trials and optimize key parameters like compaction pressure and weight percentage, which significantly influence mechanical properties. The review emphasizes the key powder metallurgy process parameters that have a significant impact on mechanical properties, becoming the primary targets for optimization. It offers a focused examination of which process parameters require thorough investigation for optimization and the suitable optimization method to achieve optimal outcomes, whether for single or multiple responses, thereby enhancing the manufacturing process. However, inconsistencies in parameter significance across studies indicate the material-dependent nature of powder metallurgy materials. The review also identifies a gap in the literature regarding secondary process optimization and comparative analyses of optimization methods. Future research should explore optimizing secondary processes in powder metallurgy, conduct comparative studies of different optimization methods, and develop novel approaches for optimization to further enhance mechanical properties and process efficiency.

Efficient phosphate and hydrogen recovery from sludge fermentation liquid by sacrificial iron anode in electro-fermentation system

Electro-fermentation (EF) has been extensively studied for recovering hydrogen and phosphorus from waste activated sludge (WAS), while was limited for the further application due to the low hydrogen yield and phosphorus recovery efficiency. This study proposed an efficient strategy for hydrogen and vivianite recovery from the simulated sludge fermentation liquid by sacrificial iron anode in EF. The optimum hydrogen productivity and the utilization efficiency of short chain fatty acids (SCFAs) reached 45.2 mmol/g COD and 77.6% at 5 d in pH 8. Phosphate removal efficiency achieved at 90.8% at 2 d and the high crystallinity and weight percentage of vivianite (84.8%) was obtained. The functional microbes, i.e., anaerobic fermentative bacteria, electrochemical active bacteria, homo-acetogens and iron-reducing bacteria were highly enriched and the inherent interaction between the microbial consortia and environmental variables was thoroughly explored. This work may provide a theoretical basis for energy/resource recovery from WAS in the further implementation.

A New Modified Carbon Paste Electrode for Selective Determination of Chromium(III) in Pharmaceutical Drugs and Food Samples

Background and Objective: This study presents a novel potentiometric method for the precise, accurate, selective, and rapid determination of Cr(III) ion concentration in different samples. Methods: A new ionophore, namely macrocyclic tetramide ionophore (MCTA), was synthesized through an inexpensive and straightforward approach, yielding a high-quality product. The (MCTA) ionophore was utilized as the active center in the preparation of modified carbon paste electrodes (MCPEs) to quantify the Cr(III) ion. The paste was made by adding graphite, MCTA, and plasticizer and mixing them in varying weight percent ratios. Results: The proposed electrodes, I and II, exhibited a trivalent Nernstian response of 20.029 ±0.57 and 20.3±0.56 mV decade-1 , respectively, with linearity of 1.0x10-7 – 1.0x10-2 and 1.0x10-5 – 1.0x10- 2 mol L-1 . Electrodes I and II were examined for their pH, response time, and thermal stability. In comparison to other mono-, bi-, and trivalent cations, starch, and sugars, the electrodes demonstrated a high degree of selectivity for Cr(III). The modified electrodes were used to determine the concentration of Cr(III) in various real samples, including drug tablets, juice extractions, and tap water, with acceptable recovery values. Conclusion: The results were compared with those obtained using the previously reported method, with no significant difference observed between them, as indicated by the F and t-test values. The data showed good accuracy and precision, as well as a high percentage of recovery. The adsorption capacity of the MCTA ionophore towards Cr(III) ions was also examined.

Multi‐response optimization of characteristics for graphite reinforced biodegradable PVA‐fumaric acid cross‐linked composite: A gray‐fuzzy logic‐based hybrid approach

AbstractIn the current investigation, enhancement in the mechanical properties, thermal stability, and decrement in the moisture absorption capabilities of polyvinyl alcohol was observed by cross‐linking it with different weight percentages (wt. %) of fumaric acid and reinforcing them along with sulfuric acid‐modified graphite particles. The effects of altering the cross‐linking duration and fumaric acid wt. % were investigated in the resulting composite using the Taguchi L16 experimental design method. As in this contemporary era of rapid industrial expansion and fierce competition, the primary goals of manufacturers revolve around the production of high‐quality goods at optimal costs within a specified timeframe. Therefore, to save both cost and time, the authors have utilized a technique known as “gray‐fuzzy optimization” to balance competing goals between mechanical (toughness, elongation and strength) and physical (water intake capacity) attributes. The present approach aimed to reduce the experimentation expenses and increase the effectiveness of composite manufacturing by considerably reducing the intricacy of practical multi‐response optimization issues. Response graphs and analysis of variance tests were also utilized to calculate the percentage contribution of the input variables and provide model significance.Highlights Polyvinyl alcohol is cross‐linked with different weight percentages (wt. %) of fumaric acid, and reinforced them with sulfuric acid‐modified graphite particles. Enhancement in mechanical properties, thermal stability, and decrease in moisture absorption capabilities were perceived for the fabricated composite. Effects of altering the cross‐linking duration and fumaric acid wt. % were investigated in the resulting composite using the Taguchi L16 experimental design. Gray‐fuzzy optimization technique was utilized to balance competing goals between water intake and mechanical attributes like toughness, elongation and strength. Response graphs and analysis of variance (ANOVA) tests were also utilized to evaluate the percentage contribution of input variables and provide model significance.

Optimization, Production, and characterization of cottonseed methyl ester based on Box-Behnken in response surface design and gas Chromatography-Mass spectrum analysis

Renewable energy sources have a significant approach to eco-friendly systems with economically cost-effective and efficient use of biodiesel. The creation of innovative catalysts is attracting the attention and concern of the chemical and manufacturing sectors to be used in the production of biodiesel. The main objective of this work is to produce the optimum biodiesel yield using BBD design and the base-catalyzed method. The production of biodiesel was achieved through experimental investigation (alkali-catalyzed transesterification) and optimized using the BBD design method.The most important parameters such as methanol to oil ratios, KOH as catalysts, and reaction times were provided with variable conditions. The variation of methanol to oil ratios has significant relationships and is highly correlated in findings. The physicochemical properties of cottonseed biodiesel were carried out according to ASTM and EN standards. The maximum yield was achieved at 96.708 at a molar ratio of 6:1, reaction time of 60 min, and catalyst concentration of 1 wt%. The strong correlation between actual and predicted values of COSME was analyzed using ANOVA variances. The F-value and P-value validated the outcomes of produced biodiesel having a model value of 43.68 and 0.00, respectively. The coefficient of determinations and adjusted R2 of CSOME were achieved at 98.7% and 98.6%, respectively. The gas chromatogram mass spectrum analysis was also obtained to identify the acid profile present in COSME. The major percentage of ester available in COSME has been determined using GC–MS analysis and presented by its weight percentages. The main esters have been including myristic acid methyl ester (1.7%), palmitic acid methyl ester (26.65%), methyl 9-cis,11-trans-octadecadienoate(44.05%), ethyl 9. Cis.11.trans octadecadienoate(9.67%), methyl 20-methyl-heneicosanoate(6.83%), 9,12-Octadecadienoic acid (Z,Z)-, 2-hydroxy-1-(hydroxymethyl)ethyl ester(1.93%), and Pentacosanoic acid, methyl ester(7.14%).

Influence of stacking sequence and nano-silica fortification on the physical properties of veli karuvelam – peepal hybrid natural composites

Abstract A hybrid composite incorporating veli karuvelam and peepal fibers was fabricated, with the addition of nanosilica as a filler to enhance composite performance. The impact of nanosilica and layering sequence on the physical properties of the composites was investigated. Initially, two types of hybrid composites i.e. peepal/veli karuvelam/peepal (PVP) and veli karuvelam/peepal/veli karuvelam (VPV) were developed by means of hand layup method, varying the layering sequence of veli karuvelam and peepal fibers. The PVP composite was identified as the most promising based on tensile strength (71 MPa), attributed to the optimal packing of high-strength peepal fibers. Subsequently, nanosilica was incorporated into the PVP composite at different weight percentages (1, 2 and 3), and its influence on composite performance was analyzed. The PVP composite containing 2 wt% SiO2 showed impressive mechanical properties, with a tensile strength of 76 MPa, a flexural strength of 104 MPa, an impact strength of 4.5 kJ/m2, and a hardness of 89 on the Shore D scale. The findings indicate that a PVP composite containing 2 wt% SiO2 has potential for use in engineering applications.

Effects of core geometry, silica nanoparticles, and polyurethane foam on the mechanical properties of a novel circular-shaped core sandwich panels under compression test: Experimental study

For the first time in this paper, a composite sandwich panel with a novel circular-shaped core reinforced with silica nanoparticles (SNPs) is designed and fabricated using the vacuum-assisted resin transfer molding (VARTM) method. Carbon fibers and epoxy resin are utilized to construct the composite sandwich panels, followed by polyurethane foam injection. After fabrication, the sandwich panels undergo uniform compression testing to examine their mechanical behavior and properties. In this study, the effects of various parameters, such as core length, core height, weight percentage (wt.%) of SNPs, and polyurethane foam, on the compressive strength of the structure are evaluated. To validate the results, a finite element simulation of the sandwich panel compression test is performed using ABAQUS software, and the results obtained are compared with experimental data, showing good agreement. The results of this research demonstrate that adding SNPs within a specific range results in a considerable enhancement of the structural strength. Adding SNPs up to 3% leads to approximately a 19% increase in the compressive strength of the structure. However, adding 4 wt.% SNPs results in a decrease of about 12% in the strength of the sandwich panel. Additionally, the core’s geometry significantly influences the control of compressive strength and rigidity of the sandwich panel. In other words, by increasing the core length, the compressive strength increases by 38%, while increasing the core height decreases compressive strength by about 30%. Also, it is found that adding polyurethane foam to the sandwich panel, despite a slight increase in weight, leads to a significant increase in compressive strength by about 32% and postpones its ultimate failure. Eventually, the hybrid specimen exhibits a strength approximately 57% greater than that of the pure foamless sandwich panel.

Curcumin’s effects on growth indices, histological scores, blood metabolites, redox state, immunity, and antioxidant-related genes of red tilapia (Oreochromis sp.)

AbstractCurcumin, a polyphenol, targets multiple signaling molecules and shows activity at the cellular level, supporting its various health benefits. Thereafter, the present study examines the effects of different doses of dietary curcumin on growth indices, feed efficiency, serum metabolites, redox (oxidation) status, immunity, histological assessment, and antioxidant-related genes in red tilapia (Oreochromis sp, Oreochromis aureus x O. mossambicus). A total of 1200 red tilapia with an average weight of 19.1±0.03 g were distributed in 12 cement ponds (3×3.5×1m). Each treatment was assigned three pounds (n=100 replicates). For 60 days, fish were fed baseline diets containing 0, 0.4, 0.6, and 0.8 g of curcumin/kg of diet. The treated fish showed increased body weight and SGR (specific growth rate) compared to the T0 group (P&lt;0.05). Curcumin in the diet significantly improved weight gain, percentages, and FCR (feed conversion ratio), with a dose-dependent effect (P &lt; 0.05). Curcumin supplementation showed no influence on feed intake, fish mortality, or survival rate (P &gt;0.05). The curcumin-treated fish groups improved tissue structure in hepatocytes, pancreatic lumens, hepatic blood sinusoids, and intestine tissue layers, particularly the mucosal layer. The T0.8 group had reduced liver enzymes (AST and ALT) and greater total protein and albumin levels (P&lt;0.05). The T0.6 and T0.8 groups showed significantly lower MDA levels than the other groups (P &lt; 0.05). Curcumin groups demonstrated significantly higher antioxidant indices (CAT, GPx, and SOD) compared to the basal diet (P&lt;0.05). Curcumin administration resulted in significant improvements in IgM and lysosome levels (P&lt;0.05). All supplemented groups had considerably (P&lt;0.05) higher levels of SOD, CAT, and GPx mRNA than the control group. Consequently, administering 0.6–0.8 g/kg of curcumin to red tilapia (Oreochromis sp.) diets may improve the fish’s growth, health, tissue composition, and antioxidant response.